Hi all, You can turn on e.g. SSE 4.1 by passing -msse4.2 to ghc. This doesn't currently imply that we compile any C code with -msse4.2 turned on, so if someone really want to use SSE4.2, they have to do: ghc -msse4,2 -optc-msse4.2 Do we want to change this so it's enough to pass -msse4.2 to ghc? -- Johan